Phytochemical and bioactivity insights into Pouzolzia zeylanica tuber: triterpenoid/sterol dominance with antioxidant and protein-stabilising effects

The ethanolic extract of coastal root tubers of Pouzolzia zeylanica was systematically characterised for its phytochemical composition and bioactivities. Analyses revealed positive results for phenolics and flavonoids and strong saponin reactions, with total contents of 74.39 ± 0.68 mg GAE/g (phenolics), 28.96 ± 1.10 mg QE/g (flavonoids), and 176.25 ± 7.50 mg OA-eq/g (saponins). UPLC–QTOF–MS profiling identified 158 metabolites, dominated by triterpenoid and sterol scaffolds. The extract exhibited antioxidant activity (IC50 values: DPPH 1.622 ± 0.074 mg/mL, ABTS 0.609 ± 0.110 mg/mL, FRP 0.320 ± 0.008 mg/mL) and strong anti-inflammatory potential in the BSA denaturation assay (IC50 0.024 ± 0.008 mg/mL). Enzyme inhibition was modest (IC50 values: α-amylase 301.34 ± 12.61 mg/mL; α-glucosidase 107.15 ± 5.43 mg/mL), consistent with the absence of enrichment for specific glycosidase inhibitors. These findings highlight P. zeylanica tubers as a triterpenoid- and saponin-rich matrix capable of conferring antioxidant and anti-inflammatory protection.